From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753239AbbBSS6K (ORCPT ); Thu, 19 Feb 2015 13:58:10 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:35687 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752344AbbBSS6I (ORCPT ); Thu, 19 Feb 2015 13:58:08 -0500 Date: Thu, 19 Feb 2015 10:57:56 -0800 From: Guenter Roeck To: Tony Lindgren Cc: Pantelis Antoniou , Grant Likely , Matt Porter , Koen Kooi , Ludovic Desroches , Rob Herring , Nicolas Ferre , devicetree@vger.kernel.org, Linux Kernel Mailing List , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 3/4] arm: am33xx: DT quirks for am33xx based beaglebone variants Message-ID: <20150219185756.GA8611@roeck-us.net> References: <1424271576-1952-1-git-send-email-pantelis.antoniou@konsulko.com> <1424271576-1952-4-git-send-email-pantelis.antoniou@konsulko.com> <20150219181656.GF32521@atomide.com> <9C7BFC7C-0751-4233-927F-D01AF078704B@antoniou-consulting.com> <20150219183600.GG32521@atomide.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20150219183600.GG32521@atomide.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-CTCH-PVer: 0000001 X-CTCH-Spam: Unknown X-CTCH-VOD: Unknown X-CTCH-Flags: 0 X-CTCH-RefID: str=0001.0A020201.54E63240.008A,ss=1,re=0.001,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-CTCH-Score: 0.001 X-CTCH-ScoreCust: 0.000 X-CTCH-Rules: C_4847, X-CTCH-SenderID: linux@roeck-us.net X-CTCH-SenderID-Flags: 0 X-CTCH-SenderID-TotalMessages: 10 X-CTCH-SenderID-TotalSpam: 0 X-CTCH-SenderID-TotalSuspected: 0 X-CTCH-SenderID-TotalConfirmed: 0 X-CTCH-SenderID-TotalBulk: 0 X-CTCH-SenderID-TotalVirus: 0 X-CTCH-SenderID-TotalRecipients: 0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: mailgid no entry from get_relayhosts_entry X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 19, 2015 at 10:36:00AM -0800, Tony Lindgren wrote: > * Pantelis Antoniou [150219 10:32]: > > > On Feb 19, 2015, at 20:16 , Tony Lindgren wrote: > > > > > > Uhh I don't like the idea of duplicating the i2c-omap.c driver under > > > arch/arm.. And in general we should initialize things later rather > > > than earlier. > > > > > > What's stopping doing these quirk checks later on time with just > > > a regular device driver, something like drivers/misc/bbone-quirks.c? > > > > > > > We have no choice; we are way early in the boot process, right after > > the device tree unflattening step. > > To me it seems the dt patching part should be done with minimal > code before any driver like features.. > > > I’ve toyed with the idea of using early platform devices but the omap-i2c driver > > would need some tender love and care to make it work, and I didn’t want to get > > bogged down with i2c driver details at this point. > > ..so how about just parse a kernel cmdline for the quirks to apply > based on a version string or similar? That can be easily populated > by u-boot or set manually with setenv. > That would not work for my use case. Again, this is a CPU card plugged into a carrier card, of which there are several variants. The CPU card is similar to a Com Express card (not exactly the same, but the same idea), so it may even be manufactured by a third party. Actually, in some cases it is. Modifying the kernel command line based on the carrier card it is connected to is simply not possible. Guenter From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@roeck-us.net (Guenter Roeck) Date: Thu, 19 Feb 2015 10:57:56 -0800 Subject: [PATCH 3/4] arm: am33xx: DT quirks for am33xx based beaglebone variants In-Reply-To: <20150219183600.GG32521@atomide.com> References: <1424271576-1952-1-git-send-email-pantelis.antoniou@konsulko.com> <1424271576-1952-4-git-send-email-pantelis.antoniou@konsulko.com> <20150219181656.GF32521@atomide.com> <9C7BFC7C-0751-4233-927F-D01AF078704B@antoniou-consulting.com> <20150219183600.GG32521@atomide.com> Message-ID: <20150219185756.GA8611@roeck-us.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Feb 19, 2015 at 10:36:00AM -0800, Tony Lindgren wrote: > * Pantelis Antoniou [150219 10:32]: > > > On Feb 19, 2015, at 20:16 , Tony Lindgren wrote: > > > > > > Uhh I don't like the idea of duplicating the i2c-omap.c driver under > > > arch/arm.. And in general we should initialize things later rather > > > than earlier. > > > > > > What's stopping doing these quirk checks later on time with just > > > a regular device driver, something like drivers/misc/bbone-quirks.c? > > > > > > > We have no choice; we are way early in the boot process, right after > > the device tree unflattening step. > > To me it seems the dt patching part should be done with minimal > code before any driver like features.. > > > I?ve toyed with the idea of using early platform devices but the omap-i2c driver > > would need some tender love and care to make it work, and I didn?t want to get > > bogged down with i2c driver details at this point. > > ..so how about just parse a kernel cmdline for the quirks to apply > based on a version string or similar? That can be easily populated > by u-boot or set manually with setenv. > That would not work for my use case. Again, this is a CPU card plugged into a carrier card, of which there are several variants. The CPU card is similar to a Com Express card (not exactly the same, but the same idea), so it may even be manufactured by a third party. Actually, in some cases it is. Modifying the kernel command line based on the carrier card it is connected to is simply not possible. Guenter